摘要：
Background and purpose The image quality of single-energy CT (SECT) limited the accuracy of automatic segmentation. Dual-energy CT (DECT) may potentially improve automatic segmentation yet the performance and strategy have not been investigated thoroughly. Based on DECT-generated virtual monochromatic images (VMIs), this study proposed a novel deep learning model (MIAU-Net) and evaluated the segmentation performance on the head organs-at-risk (OARs).
The image quality of single-energy CT (SECT) limited the accuracy of automatic segmentation. Dual-energy CT (DECT) may potentially improve automatic segmentation yet the performance and strategy have not been investigated thoroughly. Based on DECT-generated virtual monochromatic images (VMIs), this study proposed a novel deep learning model (MIAU-Net) and evaluated the segmentation performance on the head organs-at-risk (OARs).
Methods and Materials The VMIs from 40 keV to 190 keV were retrospectively generated at intervals of 10 keV using the DECT of 46 patients. Images with expert delineation were used for training, validation, and testing MIAU-Net for automatic segmentation. The performance of MIAU-Net was compared with the existing U-Net, Attention-UNet, nnU-Net and TransFuse methods based on Dice Similarity Coefficient (DSC). Correlation analysis was performed to evaluate and optimize the impact of different virtual energies on the accuracy of segmentation.
The VMIs from 40 keV to 190 keV were retrospectively generated at intervals of 10 keV using the DECT of 46 patients. Images with expert delineation were used for training, validation, and testing MIAU-Net for automatic segmentation. The performance of MIAU-Net was compared with the existing U-Net, Attention-UNet, nnU-Net and TransFuse methods based on Dice Similarity Coefficient (DSC). Correlation analysis was performed to evaluate and optimize the impact of different virtual energies on the accuracy of segmentation.
Results Using MIAU-Net, average DSCs across all virtual energy levels were 93.78 %, 81.75 %, 84.46 %, 92.85 %, 94.40 %, and 84.75 % for the brain stem, optic chiasm, lens, mandible, eyes, and optic nerves, respectively, higher than the previous publications using SECT. MIAU-Net achieved the highest average DSC (88.84 %) and the lowest parameters (14.54 M) in all tested models. The results suggested that 60 keV-80 keV is the optimal VMI energy level for soft tissue delineation, while 100 keV is optimal for skeleton segmentation.
Using MIAU-Net, average DSCs across all virtual energy levels were 93.78 %, 81.75 %, 84.46 %, 92.85 %, 94.40 %, and 84.75 % for the brain stem, optic chiasm, lens, mandible, eyes, and optic nerves, respectively, higher than the previous publications using SECT. MIAU-Net achieved the highest average DSC (88.84 %) and the lowest parameters (14.54 M) in all tested models. The results suggested that 60 keV-80 keV is the optimal VMI energy level for soft tissue delineation, while 100 keV is optimal for skeleton segmentation.
Conclusions This work proposed and validated a novel deep learning model for automatic segmentation based on DECT, suggesting potential advantages and OAR-specific optimal energy of using VMIs for automatic delineation.
This work proposed and validated a novel deep learning model for automatic segmentation based on DECT, suggesting potential advantages and OAR-specific optimal energy of using VMIs for automatic delineation.
摘要：
The CR-39 solid-state nuclear track detector is a commonly used instrument for passively measuring radon. When using CR-39 to measure the radon exhalation rate from the surface of a medium, the effects of leakage are often overlooked. However, to a certain extent, system leakage can affect the accuracy of the measurement results. Therefore, the effect of different effective decay constants (including leakage) on the radon exhalation rate is worth studying. In this study, both theoretical and experimental validation methods were used to verify the effect of the uncertainty of the effective decay constant on the results of CR-39 measurements of radon exhalation rate from the medium surface. In the theoretical validation, different values of radon exhalation rate can be obtained by substituting different effective decay constants into the CR-39 formula for measuring radon exhalation rate while keeping the other variables constant. In the experimental validation, the radon exhalation rate in the same medium was measured using both CR-39 and RAD7. Since the traditional passive method (CR-39 solid-state nuclear track detector) cannot directly obtain the effective decay constant, the effective decay constant in the CR-39 measurement experiment was replaced by the effective decay constant value fitted from the RAD7 experimental data. The results showed that the radon exhalation rate value measured by CR-39 was much larger than that measured by RAD7. From the theoretical and experimental validation, it is concluded that the uncertainty of the effective decay constant has a significant effect on the radon exhalation rate measured by CR-39.
The CR-39 solid-state nuclear track detector is a commonly used instrument for passively measuring radon. When using CR-39 to measure the radon exhalation rate from the surface of a medium, the effects of leakage are often overlooked. However, to a certain extent, system leakage can affect the accuracy of the measurement results. Therefore, the effect of different effective decay constants (including leakage) on the radon exhalation rate is worth studying. In this study, both theoretical and experimental validation methods were used to verify the effect of the uncertainty of the effective decay constant on the results of CR-39 measurements of radon exhalation rate from the medium surface. In the theoretical validation, different values of radon exhalation rate can be obtained by substituting different effective decay constants into the CR-39 formula for measuring radon exhalation rate while keeping the other variables constant. In the experimental validation, the radon exhalation rate in the same medium was measured using both CR-39 and RAD7. Since the traditional passive method (CR-39 solid-state nuclear track detector) cannot directly obtain the effective decay constant, the effective decay constant in the CR-39 measurement experiment was replaced by the effective decay constant value fitted from the RAD7 experimental data. The results showed that the radon exhalation rate value measured by CR-39 was much larger than that measured by RAD7. From the theoretical and experimental validation, it is concluded that the uncertainty of the effective decay constant has a significant effect on the radon exhalation rate measured by CR-39.
作者机构：
[Liu, Jinquan; Xiao, Xilin; Wu, Qian; Xiao, XL; Liu, Zhen] Univ South China, Sch Publ Hlth, Hengyang Sch Med, Hengyang, Hunan, Peoples R China.;[Liu, Xing] Univ South China, Sch Nucl Sci & Technol, Hengyang, Hunan, Peoples R China.;[Xiao, Xilin; Xiao, XL] Hunan Univ, State Key Lab Chemo Biosensing & Chemometr, Changsha, Hunan, Peoples R China.
通讯机构：
[Xiao, XL ] U;Univ South China, Sch Publ Hlth, Hengyang Sch Med, Hengyang, Hunan, Peoples R China.;Hunan Univ, State Key Lab Chemo Biosensing & Chemometr, Changsha, Hunan, Peoples R China.
摘要：
Food is essential for the proper functioning of the human body, and small molecule contaminants, such as antibiotics, have become a growing concern due to their harmful effects on both biological systems and the environment. These contaminants can enter the food supply through the use of antibiotics in animals, potentially causing significant health and ecological damage. As a result, detecting these pollutants, especially at trace levels, has become increasingly important. Aptamer sensors have gained popularity for this purpose because of their high stability, specificity, ease of modification, and low cost. To improve the sensitivity of these sensors, various signal enhancement strategies are used. These strategies aim to better detect small molecule contaminants, with many relying on nanomaterials and nucleic acid amplification techniques to amplify signals. Nanomaterials, which come in different forms such as zero-dimensional, one-dimensional, two-dimensional, and three-dimensional, play a crucial role in improving the performance of these sensors. This article provides an overview of these signal enhancement approaches, discussing the challenges and potential future directions for the development of aptamers in food contamination detection.
作者机构：
[Xiao, Xilin; Wu, Qian; Liu, Zhen] Univ South China, Sch Publ Hlth, Hengyang Sch Med, Dept Publ Hlth Lab Sci, Hengyang, Hunan, Peoples R China.;[Liu, Xing] Univ South China, Sch Nucl Sci & Technol, Hengyang, Hunan, Peoples R China.;[Xiao, Xilin] Hunan Univ, State Key Lab Chemo Biosensing & Chemometr, Changsha, Hunan, Peoples R China.
通讯机构：
[Xiao, XL ] U;Univ South China, Sch Publ Hlth, Hengyang Sch Med, Dept Publ Hlth Lab Sci, Hengyang, Hunan, Peoples R China.;Hunan Univ, State Key Lab Chemo Biosensing & Chemometr, Changsha, Hunan, Peoples R China.
关键词：
Fluorescent sensor;Catalytic hairpin assembly;Cascade isothermal signal amplification;Kanamycin
摘要：
This study employs a guanine (G)-rich DNA sequence as the recognition element and integrates exonuclease III (Exo III) with a mismatch catalytic hairpin assembly (MCHA)-based cascade isothermal signal amplification strategy to construct a novel fluorescent DNA biosensor for the highly sensitive detection of kanamycin (Kana). In the presence of the target, the recognition element HP1 is unfolded by the target and forms a double-stranded HP1-HP2 structure with HP2. This structure is subsequently cleaved by Exo III, releasing the trigger strand of MCHA. The trigger strand binds to H1, which contains dual fluorescent groups, resulting in the separation of carboxyfluorescein (FAM) and tetramethylrhodamine (TAMRA). This separation attenuates fluorescence resonance energy transfer and restores FAM fluorescence, generating a strong fluorescence signal at 520 nm. The fluorescence sensor demonstrates a linear detection range from 2 to 12 nM, with a detection limit of 0.16 nM. In real milk samples, the spiked recovery rate ranges from 97.4 to 106.3%, with relative standard deviations between 2.2 and 3.8%. The cascade isothermal signal amplification strategy significantly enhances the sensor's sensitivity, while MCHA reduces false positive rates. This aptamer-based sensor exhibits excellent specificity, minimal susceptibility to interference, and suitability for detecting Kana in milk.
期刊：
Journal of Environmental Radioactivity,2025年286:107685 ISSN：0265-931X
通讯作者：
Tang, B;Zeng, WJ
作者机构：
[Tang, Bing; Guo, Chong] Univ South China, Affiliated Hosp 2, Hengyang 421001, Peoples R China.;[Li, Xiaoyu; Zeng, Wenjie; Zeng, WJ; Guo, Chong; Yan, Zhihui] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chen, Lekang] Beihang Univ, Sch Phys, Beijing 100191, Peoples R China.
通讯机构：
[Zeng, WJ ; Tang, B ] U;Univ South China, Affiliated Hosp 2, Hengyang 421001, Peoples R China.;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
Air absorbed dose rate;Bi-LSTM;CNN;Deep learning model;Prediction method
摘要：
Air absorbed dose rate is a key indicator of environmental radiation exposure. In China, automated environmental radiation monitoring systems have been established in multiple cities to continuously measure air absorbed dose rates. Nevertheless, developing effective preventive strategies based solely on data monitoring remains challenging. To address the issue, this study proposes a prediction framework for urban air absorbed dose rates based on historical data. The framework encompasses model construction, data preprocessing, outcome evaluation and prediction of future data. Specifically, three deep learning models—Long Short-Term Memory (LSTM), Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM), and Bidirectional Long Short-Term Memory (Bi-LSTM)—were employed to develop prediction methods for urban air absorbed dose rates. Given the large and complex dataset structure of air absorbed dose rates reports released by the National Nuclear Safety Administration, a Convolutional Neural Network (CNN) was utilized to extract monitoring data, significantly improving data preprocessing efficiency. Missing values were handled using Lagrange interpolation method. The results showed that the Bi-LSTM model performed best in terms of coefficient of determination (R 2 ), mean absolute error (MAE) and root mean square error (RMSE) when predicting the air absorbed dose rates in a coastal city. When predicting the air absorbed dose rates in an inland city, the R 2 and RMSE indices of the Bi-LSTM model are more accurate, although the MAE value of the Bi-LSTM model is slightly higher than that of the LSTM model. To summarize, the Bi-LSTM model is more effective in predicting the air absorbed dose rates in Chinese cities.
Air absorbed dose rate is a key indicator of environmental radiation exposure. In China, automated environmental radiation monitoring systems have been established in multiple cities to continuously measure air absorbed dose rates. Nevertheless, developing effective preventive strategies based solely on data monitoring remains challenging. To address the issue, this study proposes a prediction framework for urban air absorbed dose rates based on historical data. The framework encompasses model construction, data preprocessing, outcome evaluation and prediction of future data. Specifically, three deep learning models—Long Short-Term Memory (LSTM), Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM), and Bidirectional Long Short-Term Memory (Bi-LSTM)—were employed to develop prediction methods for urban air absorbed dose rates. Given the large and complex dataset structure of air absorbed dose rates reports released by the National Nuclear Safety Administration, a Convolutional Neural Network (CNN) was utilized to extract monitoring data, significantly improving data preprocessing efficiency. Missing values were handled using Lagrange interpolation method. The results showed that the Bi-LSTM model performed best in terms of coefficient of determination (R 2 ), mean absolute error (MAE) and root mean square error (RMSE) when predicting the air absorbed dose rates in a coastal city. When predicting the air absorbed dose rates in an inland city, the R 2 and RMSE indices of the Bi-LSTM model are more accurate, although the MAE value of the Bi-LSTM model is slightly higher than that of the LSTM model. To summarize, the Bi-LSTM model is more effective in predicting the air absorbed dose rates in Chinese cities.
期刊：
Journal of Environmental Radioactivity,2025年287:107702 ISSN：0265-931X
通讯作者：
Anguo Peng
作者机构：
[Chen, Mengting; Li, Xuebin; Wu, Mengxing; He, Husheng] School of Nuclear Science and Technology, University of South China, Hengyang 421001, Hunan, China;[Peng, Anguo] School of Nuclear Science and Technology, University of South China, Hengyang 421001, Hunan, China. Electronic address: 2008000463@usc.edu.cn
通讯机构：
[Anguo Peng] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, Hunan, China
关键词：
(137)Cs;(210)Pb(ex);(239+240)Pu;Dongting Lake;Mass accumulation rate;Spatial distribution
摘要：
In this study, 24 sediment cores collected from Dongting Lake were detected by inductively coupled plasma-mass spectrometry and HPGe γ-spectrometer for 239+240 Pu, 137 Cs, 226 Ra, and 210 Pb, respectively. Based on the vertical profiles of 210 Pb ex , 239+240 Pu, and 137 Cs, sediment mass accumulation rates (MAR) were calculated, and the responses to major environmental events and anthropogenic activities were discussed. The vertical profiles of 137 Cs and 239+240 Pu exhibit bimodal distribution, the secondary peaks most probably indicated the fallout from a series of Chinese nuclear tests (CNT) during the 1970s. Comparisons of the Constant Initial Concentration (CIC) model, the Constant Flux Constant Sedimentation (CFCS) model, and the Constant Rate of Supply (CRS) model reveal that some sites in Dongting Lake are unsuitable for 210 Pb ex dating. The MARs derived from different methods show the spatial distribution characteristics in the order of West Dongting Lake (WDL) > South Dongting Lake (SDL) > East Dongting Lake (EDL). Comparisons of the three methods confirm that the 210 Pb ex method is a valuable tool for evaluating the impact of environmental changes and human activities in different periods. In this study, the MARs derived from the 210 Pb ex method show significant correlations with hydrological data and accurately reflect key environmental change events in Dongting Lake, including the widespread drought in 2011, the operation of the Three Gorges Dam in 2006, the major flood in 1998, and localized flooding events in the Yuan River and Xiangjiang River.
In this study, 24 sediment cores collected from Dongting Lake were detected by inductively coupled plasma-mass spectrometry and HPGe γ-spectrometer for 239+240 Pu, 137 Cs, 226 Ra, and 210 Pb, respectively. Based on the vertical profiles of 210 Pb ex , 239+240 Pu, and 137 Cs, sediment mass accumulation rates (MAR) were calculated, and the responses to major environmental events and anthropogenic activities were discussed. The vertical profiles of 137 Cs and 239+240 Pu exhibit bimodal distribution, the secondary peaks most probably indicated the fallout from a series of Chinese nuclear tests (CNT) during the 1970s. Comparisons of the Constant Initial Concentration (CIC) model, the Constant Flux Constant Sedimentation (CFCS) model, and the Constant Rate of Supply (CRS) model reveal that some sites in Dongting Lake are unsuitable for 210 Pb ex dating. The MARs derived from different methods show the spatial distribution characteristics in the order of West Dongting Lake (WDL) > South Dongting Lake (SDL) > East Dongting Lake (EDL). Comparisons of the three methods confirm that the 210 Pb ex method is a valuable tool for evaluating the impact of environmental changes and human activities in different periods. In this study, the MARs derived from the 210 Pb ex method show significant correlations with hydrological data and accurately reflect key environmental change events in Dongting Lake, including the widespread drought in 2011, the operation of the Three Gorges Dam in 2006, the major flood in 1998, and localized flooding events in the Yuan River and Xiangjiang River.
摘要：
The transition metal sulfide-activated peroxymonosulfate (PMS) has been proven to be a promising alternative for removing organic pollutants. However, the interaction among active sites was not fully elucidated. To clarify this issue, a simple nickel sulfide with sulfur vacancies (NSHC10-400) via the hydrothermal-calcination successive treatments was successfully fabricated and employed for activating PMS for Acid Orange II (AOII) removal. The results showed that the Ni 2+ , reductive sulfur species and sulfur vacancies acted as main active sites on the activation of PMS. Due to their synergistic effect, the NSHC10-400 exhibited extraordinary catalytic activity, degrading nearly complete AOII only for 1.0 min with small PMS concentration. Besides, it still kept high degradation in the existence of foreign interference. The electron spin resonance and quenching experiments indicated that both radical and non-radical species jointly contributed to the degradation of AOII. Finally, the bio-toxicity of solution was reduced after the reaction. Overall, this work provided an effective process for removing organic pollutants from the wastewater.
The transition metal sulfide-activated peroxymonosulfate (PMS) has been proven to be a promising alternative for removing organic pollutants. However, the interaction among active sites was not fully elucidated. To clarify this issue, a simple nickel sulfide with sulfur vacancies (NSHC10-400) via the hydrothermal-calcination successive treatments was successfully fabricated and employed for activating PMS for Acid Orange II (AOII) removal. The results showed that the Ni 2+ , reductive sulfur species and sulfur vacancies acted as main active sites on the activation of PMS. Due to their synergistic effect, the NSHC10-400 exhibited extraordinary catalytic activity, degrading nearly complete AOII only for 1.0 min with small PMS concentration. Besides, it still kept high degradation in the existence of foreign interference. The electron spin resonance and quenching experiments indicated that both radical and non-radical species jointly contributed to the degradation of AOII. Finally, the bio-toxicity of solution was reduced after the reaction. Overall, this work provided an effective process for removing organic pollutants from the wastewater.
摘要：
Transarterial radioembolization (TARE) using yttrium-90 ( 90 Y)-labeled glass and resin microspheres is an emerging therapeutic technique for hepatocellular carcinoma (HCC). However, the non-biodegradability and rapid settlement of current commercial microspheres might hinder their even distribution and repetitive administration thus causing unsatisfactory therapeutic effects. In this context, novel functional chitosan-based microspheres (CPIs) that can efficiently label Y as a favorable TARE material were developed for the first time by successive grafting poly (glycidyl methacrylate) (PGMA) and iminodiacetic acid (IDA) onto chitosan microspheres (CMs). The results confirmed that the CPIs had desirable spherical shapes with average diameters of around 20.9 μm, an ideal settlement rate within 5 min, and considerable biodegradability at 10th weeks. It reached Y adsorption equilibrium within 30 min and maintained the maximum adsorption capacity up to 14.95 mg g −1 at pH 6.0 following pseudo-second-order kinetic and Langmuir models. Additionally, Y-labeled CPIs were rather stable in vitro, for which Y would firmly interact with the sodium carboxylate group and tertiary amine nitrogen atoms on IDA, and its leakage when shaken in phosphate-buffered saline for 24 h was barely detected. Altogether, these properties of the as-developed CPIs hold great potential as promising radioembolization microspheres for TARE therapy against liver cancer.
Transarterial radioembolization (TARE) using yttrium-90 ( 90 Y)-labeled glass and resin microspheres is an emerging therapeutic technique for hepatocellular carcinoma (HCC). However, the non-biodegradability and rapid settlement of current commercial microspheres might hinder their even distribution and repetitive administration thus causing unsatisfactory therapeutic effects. In this context, novel functional chitosan-based microspheres (CPIs) that can efficiently label Y as a favorable TARE material were developed for the first time by successive grafting poly (glycidyl methacrylate) (PGMA) and iminodiacetic acid (IDA) onto chitosan microspheres (CMs). The results confirmed that the CPIs had desirable spherical shapes with average diameters of around 20.9 μm, an ideal settlement rate within 5 min, and considerable biodegradability at 10th weeks. It reached Y adsorption equilibrium within 30 min and maintained the maximum adsorption capacity up to 14.95 mg g −1 at pH 6.0 following pseudo-second-order kinetic and Langmuir models. Additionally, Y-labeled CPIs were rather stable in vitro, for which Y would firmly interact with the sodium carboxylate group and tertiary amine nitrogen atoms on IDA, and its leakage when shaken in phosphate-buffered saline for 24 h was barely detected. Altogether, these properties of the as-developed CPIs hold great potential as promising radioembolization microspheres for TARE therapy against liver cancer.
摘要：
PURPOSE: This first-in-human study aimed to evaluate the radiation dosimetry and whole-body biodistribution of [(18)F]AlF-NYM005, a novel small-molecule carbonic anhydrase IX (CAIX) targeting agent, and to investigate its ability to detect CAIX-positive tumors using PET scans in a cohort of clear cell renal cell carcinoma (ccRCC) patients. METHODS: [(18)F]AlF-NYM005 was synthesized using a fully automatic cassette module Mortenon M1 (Nuoyu, China). Thirty-five patients with a suspicious lesion considered primary renal malignancy or a history of ccRCC were prospectively recruited and studied. All patients underwent [(18)F]AlF-NYM005 PET/CT examinations and the maximum standardized uptake value (SUVmax) was measured on conventional [(18)F]AlF-NYM005 PET/CT images. Among these patients, five patients underwent dynamic [(18)F]AlF-NYM005 PET/CT scanning (120min) of the lower abdomen. Another subset of five ccRCC patients underwent sequential whole-body PET scans at 30, 60, 90, and 120min (one of the five patients underwent additional 150min and 180min scans) after [(18)F]AlF-NYM005 injection to assess biodistribution and dosimetry. The influx constant (Ki) was calculated from the dynamic [(18)F]AlF-NYM005 PET/CT data using the Patlak model. Whole-body biodistribution was calculated as time-activity curves (TACs) describing dynamic uptake patterns in the patients' major organs, followed by calculation of tracer kinetics and cumulative organ activity. Effective doses of [(18)F]AlF-NYM005 and individual organ doses were also calculated. RESULTS: [(18)F]AlF-NYM005 was successfully synthesized with a radiochemical purity of > 95% and an average labeling yield of 36.5 ± 8.3%. All patients tolerated the PET examinations well, and no adverse side effects were observed. The total body effective dose was 7.6E-03 mSv/MBq. The highest agent uptake was observed in the kidneys, stomach, and liver, contributing to an effective dose of 0.0126 ± 0.0029 mSv/MBq. The TACs showed optimal normal organ uptake with high tumor uptake and long retention of up to 2h post-injection. Notably, a rapid increase of the tracer followed by a rapid decrease in the blood pool, kidney, liver, and tumor lesions was observed, indicating that [(18)F]AlF-NYM005 was rapidly eliminated from blood and urine. For the kinetic data analysis, the Ki for the primary kidney lesions had a mean of 0.082 ± 0.057ml/g/min. The CAIX-positive tumors displayed rapid uptake, and all lesions were detectable within 30min, with no additional lesions observed in the subsequent multi-time point scans. The patient-level sensitivity, specificity, and accuracy of [(18)F]AlF-NYM005 PET/CT were 93.8%, 75.0%, and 90% for group 1 and 92.3%, 100%, and 93.3% for group 2, respectively. For per-lymph node analysis, [(18)F]AlF-NYM005 PET/CT demonstrated 92.9% sensitivity, 90.5% specificity, and 91.8% accuracy in diagnosing metastatic lymph nodes. For per-distant metastasis analysis, it showed 90.5% sensitivity, 91.3% specificity, and 90.6% accuracy. The SUVmax of [(18)F]AlF-NYM005 PET/CT for primary ccRCC lesions was 15.5 ± 7.35. Tumor uptake was positive correlated with immunohistochemical staining findings. CONCLUSION: This pilot study in ccRCC patients has demonstrated the safety, acceptable radiation dosimetry, favorable biodistribution, and exceptional tumor uptake of [(18)F]AlF-NYM005. The preliminary diagnostic study indicated the potential utility of [(18)F]AlF-NYM005 PET/CT, showing promising results in the diagnosis of primary or metastatic ccRCC. TRIAL REGISTRATION: This study was registered at ClinicalTrial.gov (ChiCTR2200058108) as NYPILOT on 29 March, 2022.
摘要：
The copper-based materials were considered as promising catalysts for the activation of peroxydisulfate (PDS), but the study on the Cu 2 S-activated PDS under LED illumination and alkaline condition was little reported. In this work, Cu 2 S, a simple and readily available heterogeneous catalyst, was employed to enhance the activation of PDS under alkaline condition through LED illumination. The results indicated that under LED illumination, the degradation rate of tetracycline (TC) during the first 15 min was 3.55 times higher than that of the darkness. A series of important influencing factors were optimized, including anions, humic acid and complex water matrices. The results showed that the Cu 2 S/PDS/LED system exhibited excellent adaptability. Besides, the Cu 2 S maintained a good stability. The quenching experiments and electron spin resonance analysis demonstrated that the electron transfer and singlet oxygen were two primary pathways for the degradation of TC, and also other species such as sulfate and hydroxyl radicals played important roles. Furthermore, X-ray photoelectron spectroscopy characterization and a series of experiments confirmed that the Cu + was the primary catalytic active sites, while the reductive sulfur species could directly activate PDS and accelerate the circulation of Cu 2+ /Cu + . The toxicity test proved that the toxicity of TC was decreased after the degradation. This study not only highlighted the potential of the Cu 2 S/PDS/LED system for efficient TC degradation under alkaline condition but also provided new insight for the development of Cu-based catalytic technology.
The copper-based materials were considered as promising catalysts for the activation of peroxydisulfate (PDS), but the study on the Cu 2 S-activated PDS under LED illumination and alkaline condition was little reported. In this work, Cu 2 S, a simple and readily available heterogeneous catalyst, was employed to enhance the activation of PDS under alkaline condition through LED illumination. The results indicated that under LED illumination, the degradation rate of tetracycline (TC) during the first 15 min was 3.55 times higher than that of the darkness. A series of important influencing factors were optimized, including anions, humic acid and complex water matrices. The results showed that the Cu 2 S/PDS/LED system exhibited excellent adaptability. Besides, the Cu 2 S maintained a good stability. The quenching experiments and electron spin resonance analysis demonstrated that the electron transfer and singlet oxygen were two primary pathways for the degradation of TC, and also other species such as sulfate and hydroxyl radicals played important roles. Furthermore, X-ray photoelectron spectroscopy characterization and a series of experiments confirmed that the Cu + was the primary catalytic active sites, while the reductive sulfur species could directly activate PDS and accelerate the circulation of Cu 2+ /Cu + . The toxicity test proved that the toxicity of TC was decreased after the degradation. This study not only highlighted the potential of the Cu 2 S/PDS/LED system for efficient TC degradation under alkaline condition but also provided new insight for the development of Cu-based catalytic technology.
摘要：
Ammonium phosphomolybdate (APM) is often used for the adsorption of Cs + . However, the decomposition temperature of cesium-containing ammonium phosphomolybdate waste is low and difficult to dispose of. This study introduces the first use of cold sintering to solidify ammonium phosphomolybdate monomers at low temperatures. The maximum adsorption capacity of the synthesized ammonium phosphomolybdate was 112.58 mg/g. Cold sintering results indicate that the HNO 3 was more effective than other acidic or salt solutions for densifying ammonium phosphomolybdate. The optimal conditions for cold sintering were 200 °C, 500 MPa, 10 wt% HNO 3 , and 10 min. The cold-sintered Cs-ammonium phosphomolybdate ceramic exhibited impressive compressive strength (624.7 MPa), Vickers microhardness (165.2 HV) and relative density of (97.61 %). The Cs leaching rate of Cs-ammonium phosphomolybdate ceramics was as low as 7.38 × 10 −5 g m −2 ·d −1 after measured at 90 °C for 7 days.
Ammonium phosphomolybdate (APM) is often used for the adsorption of Cs + . However, the decomposition temperature of cesium-containing ammonium phosphomolybdate waste is low and difficult to dispose of. This study introduces the first use of cold sintering to solidify ammonium phosphomolybdate monomers at low temperatures. The maximum adsorption capacity of the synthesized ammonium phosphomolybdate was 112.58 mg/g. Cold sintering results indicate that the HNO 3 was more effective than other acidic or salt solutions for densifying ammonium phosphomolybdate. The optimal conditions for cold sintering were 200 °C, 500 MPa, 10 wt% HNO 3 , and 10 min. The cold-sintered Cs-ammonium phosphomolybdate ceramic exhibited impressive compressive strength (624.7 MPa), Vickers microhardness (165.2 HV) and relative density of (97.61 %). The Cs leaching rate of Cs-ammonium phosphomolybdate ceramics was as low as 7.38 × 10 −5 g m −2 ·d −1 after measured at 90 °C for 7 days.
摘要：
Purpose Investigating the effects of unequal sub-arc personalized collimator angle selection on the quality of Volumetric Modulated Arc Therapy (VMAT) plans for treating multiple brain metastases.
Investigating the effects of unequal sub-arc personalized collimator angle selection on the quality of Volumetric Modulated Arc Therapy (VMAT) plans for treating multiple brain metastases.
Methods This study included 21 patients, each with 2–4 target volumes of multiple brain metastases. Two stereotactic radiotherapy (SRT) approaches were utilized: sub-arc collimator VMAT (SAC-VMAT) and fixed collimator VMAT (FC-VMAT). In the SAC-VMAT group, multi-leaf collimators (MLC) shaped the target area, dividing the full arc into four unequal sub-arcs under the beam's eye view (BEV). Each sub-arc had an appropriate collimator angle selected to mitigate ‘island blocking problems'. Conversely, the FC-VMAT group used a fixed collimator angle of 15° or 345°. A comparative analysis of the dosimetric parameters of the target volumes and normal tissues, along with the monitor units (MU), was conducted between the two groups.
This study included 21 patients, each with 2–4 target volumes of multiple brain metastases. Two stereotactic radiotherapy (SRT) approaches were utilized: sub-arc collimator VMAT (SAC-VMAT) and fixed collimator VMAT (FC-VMAT). In the SAC-VMAT group, multi-leaf collimators (MLC) shaped the target area, dividing the full arc into four unequal sub-arcs under the beam's eye view (BEV). Each sub-arc had an appropriate collimator angle selected to mitigate ‘island blocking problems'. Conversely, the FC-VMAT group used a fixed collimator angle of 15° or 345°. A comparative analysis of the dosimetric parameters of the target volumes and normal tissues, along with the monitor units (MU), was conducted between the two groups.
Results The mean dose and dose-volume to normal brain tissue (2–26 Gy, with a step of 2 Gy) were significantly lower in the SAC-VMAT group (P < 0.01). There was no statistical difference between the two groups in dose to the target volumes, conformity index (CI), homogeneity index (HI), and other normal tissues (P > 0.05). Compared with the FA-VMAT group, the SAC-VMAT group significantly reduced the gradient index (GI) (4.5 ± 0.59 vs 5.2 ± 0.75, P < 0.001) and MU (1774.33 ± 181.77 vs 2001.0 ± 344.86, P < 0.001). Notably, with an increase in the number of PTV, the SAC-VMAT group demonstrated more significant improvements in the dose-volume of normal brain tissue, GI, and MU.
The mean dose and dose-volume to normal brain tissue (2–26 Gy, with a step of 2 Gy) were significantly lower in the SAC-VMAT group (P < 0.01). There was no statistical difference between the two groups in dose to the target volumes, conformity index (CI), homogeneity index (HI), and other normal tissues (P > 0.05). Compared with the FA-VMAT group, the SAC-VMAT group significantly reduced the gradient index (GI) (4.5 ± 0.59 vs 5.2 ± 0.75, P < 0.001) and MU (1774.33 ± 181.77 vs 2001.0 ± 344.86, P < 0.001). Notably, with an increase in the number of PTV, the SAC-VMAT group demonstrated more significant improvements in the dose-volume of normal brain tissue, GI, and MU.
Conclusions In this study, personalized selection of the unequal sub-arc collimator angle ensured the prescribed dose to the PTV, CI, and HI, while significantly reducing the GI, MU, and the dose to normal brain tissue in the VMAT plan for multi-target brain metastases in the cohort of cases with 2–4 target volumes. Particularly as the number of targets increase, the advantages of this method become more pronounced.
In this study, personalized selection of the unequal sub-arc collimator angle ensured the prescribed dose to the PTV, CI, and HI, while significantly reducing the GI, MU, and the dose to normal brain tissue in the VMAT plan for multi-target brain metastases in the cohort of cases with 2–4 target volumes. Particularly as the number of targets increase, the advantages of this method become more pronounced.
作者机构：
[Guo, Yuqi; Xu, Dachuan; Li, Can] Beijing Univ Technol, Inst Operat Res & Informat Engn, Beijing 100124, Peoples R China.;[Lin, Xinyan; Feng, Xuezhen; Yang, Ruijie] Peking Univ Third Hosp, Canc Ctr, Dept Radiat Oncol, Beijing 100191, Peoples R China.;[Lin, Xinyan] Beihang Univ, Sch Phys, Beijing 102206, Peoples R China.;[Feng, Xuezhen] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构：
[Yang, RJ ] P;Peking Univ Third Hosp, Canc Ctr, Dept Radiat Oncol, Beijing 100191, Peoples R China.
关键词：
Deep reinforcement learning;Radiation therapy;Treatment planning
摘要：
PURPOSE: The formulation and optimization of radiation therapy plans are complex and time-consuming processes that heavily rely on the expertise of medical physicists. Consequently, there is an urgent need for automated optimization methods. Recent advancements in reinforcement learning, particularly deep reinforcement learning (DRL), show great promise for automating radiotherapy planning. This review summarizes the current state of DRL applications in this field, evaluates their effectiveness, and identifies challenges and future directions. METHODS: A systematic search was conducted in Google Scholar, PubMed, IEEE Xplore, and Scopus using keywords such as "deep reinforcement learning", "radiation therapy", and "treatment planning". The extracted data were synthesized for an overview and critical analysis. RESULTS: The application of deep reinforcement learning in radiation therapy plan optimization can generally be divided into three categories: optimizing treatment planning parameters, directly optimizing machine parameters, and adaptive radiotherapy. From the perspective of disease sites, DRL has been applied to cervical cancer, prostate cancer, vestibular schwannoma, and lung cancer. Regarding types of radiation therapy, it has been used in HDRBT, IMRT, SBRT, VMAT, GK, and Cyberknife. CONCLUSIONS: Deep reinforcement learning technology has played a significant role in advancing the automated optimization of radiation therapy plans. However, there is still a considerable gap before it can be widely applied in clinical settings due to three main reasons: inefficiency, limited methods for quality assessment, and poor interpretability. To address these challenges, significant research opportunities exist in the future, such as constructing evaluators, parallelized training, and exploring continuous action spaces.
关键词：
Adaptive radiotherapy;CBCT;Deformable image registration;Lung cancer
摘要：
This study employed a commercial software velocity to perform deformable registration and dose calculation on deformed CT images, aiming to assess the accuracy of dose delivery during the radiotherapy for lung cancers. A total of 20 patients with lung cancer were enrolled in this study. Adaptive CT (ACT) was generated by deformed the planning CT (pCT) to the CBCT of initial radiotherapy fraction, followed by contour propagation and dose recalculation. There was not significant difference between volumes of GTV and CTV calculated from the ACT and pCT. However, significant differences in dice similarity coefficient (DSC) and coverage ratio (CR) between GTV and CTV were observed, with lower values for GTV volumes below 15cc. The mean differences in dose corresponding to 95% of the GTV, GTV-P, CTV, and CTV-P between ACT and pCT were - 0.32%, 4.52%, 2.17%, and 4.71%, respectively. For the dose corresponding to 99%, the discrepancies were - 0.18%, 8.35%, 1.92%, and 24.96%, respectively. These differences in dose primarily appeared at the edges of the target areas. Notably, a significant enhancement of dose corresponding to 1cc for spinal cord was observed in ACT, compared with pCT. There was no statistical difference in the mean dose of lungs and heart. In general, for lung cancer patients, anatomical motion may result in both CTV and GTV moving outside the original irradiation region. The dose difference within the original target area was small, but the difference in the planning target area was considerable.
摘要：
The preoperative identification of tumor grade in chondrosarcoma (CS) is crucial for devising effective treatment strategies and predicting outcomes. The study aims to build and validate a CT-based radiomics nomogram (RN) for the preoperative identification of tumor grade in CS, and to evaluate the correlation between the RN-predicted tumor grade and postoperative outcome. A total of 196 patients (139 in the training cohort and 57 in the external validation cohort) were derived from three different centers. A clinical model, radiomics signature (RS) and RN (which combines significant clinical factors and RS) were developed and validated to assess their ability to distinguish low-grade from high-grade CS with area under the curve (AUC). Additionally, Kaplan-Meier survival analysis was applied to examine the association between RN-predicted tumor grade and recurrence-free survival (RFS) of CS. The predictive accuracy of the RN was evaluated using Harrell’s concordance index (C-index), hazard ratio (HR) and AUC. Size, endosteal scalloping and active periostitis were selected to build the clinical model. Three radiomics features, based on CT images, were selected to construct the RS. Both the RN (AUC, 0.842) and RS (AUC, 0.835) were superior to the clinical model (AUC, 0.776) in the validation set (P = 0.003, 0.040, respectively). A correlation between Nomogram score (Nomo-score, derived from RN) and RFS was observed through Kaplan-Meier survival analysis in the training and test cohorts (log-rank P < 0.050). Patients with high Nomo-score tumors were 2.669 times more likely to suffer recurrence than those with low Nomo-score tumors (HR, 2.669, P < 0.001). The CT-based RN performed well in predicting both the histologic grade and outcome of CS.
作者机构：
[Wang, Kezheng; Yang, Liping] Harbin Med Univ, Dept PET CT, Canc Hosp, Harbin 150001, Peoples R China.;[Ding, Hongchao; Gao, Xing] Heilongjiang Prov Hosp, Dept Phys Diagnost, Harbin, Peoples R China.;[Xu, Yuchao] Univ South China, Sch Nucl Sci & Technol, Hengyang, Peoples R China.;[Xu, Shichuan; Xu, SC] Second Hosp Harbin, Dept Med Instruments, Harbin 150001, Peoples R China.
通讯机构：
[Xu, SC ] S;[Wang, KZ ] H;Harbin Med Univ, Dept PET CT, Canc Hosp, Harbin 150001, Peoples R China.;Second Hosp Harbin, Dept Med Instruments, Harbin 150001, Peoples R China.
关键词：
Breast neoplasms;Positron emission tomography- computed tomography;Radiomics;Sentinel lymph node
摘要：
BACKGROUND: Sentinel lymph node (SLN) biopsy (SLNB) is considered the gold standard for detecting SLN metastases in patients with invasive ductal breast cancer (IDC). However, SLNB is invasive and associated with several complications. Thus, this study aimed to evaluate the diagnostic performance of a non-invasive radiomics analysis utilizing 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) for assessing SLN metastasis in IDC patients. METHODS: This retrospective study included 132 patients with biopsy-confirmed IDC, who underwent (18)F-FDG PET/CT scans prior to mastectomy or breast-conserving surgery with SLNB. Tumor resection or SLNB was conducted within one-week post-scan. Clinical data and metabolic parameters were analyzed to identify independent SLN metastasis predictors. Radiomic features were extracted from each PET volume of interest (VOI) and CT-VOI. Feature selection involved univariate and multivariate logistic regression analysis, and the least absolute shrinkage and selection operator (LASSO) method. Three models were developed to predict SLN status using the random forest (RF), decision tree (DT), and k-Nearest Neighbors (KNN) classifiers. Model performance was assessed using the area under the receiver operating characteristic curve (AUC). RESULTS: The study included 91 cases (32 SLN-positive and 59 SLN-negative patients) in the training cohort and 41 cases (29 SLN-positive and 12 SLN-negative patients) in the validation cohort. Multivariate logistic regression analysis identified Ki 67 and TLG as independent predictors of SLN status. Five PET-derived features, three CT-derived features, and two clinical variables were selected for model development. The AUC values of the RF, KNN, and DT models for the training cohort were 0.887, 0.849, and 0.824, respectively, and for the validation cohort were 0.856, 0.830, and 0.819, respectively. The RF model demonstrated the highest accuracy for the preoperative prediction of SLN metastasis in IDC patients. CONCLUSION: The PET-CT radiomics approach may offer robust and non-invasive predictors for SLN status in IDC patients, potentially aiding in the planning of personalized treatment strategies for IDC patients.
摘要：
To develop and validate a radiomics nomogram combining radiomics features and clinical factors for preoperative evaluation of Ki-67 expression status and prognostic prediction in clear cell renal cell carcinoma (ccRCC). Two medical centers of 185 ccRCC patients were included, and each of them formed a training group (n = 130) and a validation group (n = 55). The independent predictor of Ki-67 expression status was identified by univariate and multivariate regression, and radiomics features were extracted from the preoperative CT images. The maximum relevance minimum redundancy (mRMR) and the least absolute shrinkage and selection operator algorithm (LASSO) were used to identify the radiomics features that were most relevant for high Ki-67 expression. Subsequently, clinical model, radiomics signature (RS), and radiomics nomogram were established. The performance for prediction of Ki-67 expression status was validated using area under curve (AUC), calibration curve, Delong test, decision curve analysis (DCA). Prognostic prediction was assessed by survival curve and concordance index (C-index). Tumour size was the only independent predictor of Ki-67 expression status. Five radiomics features were finally identified to construct the RS (AUC: training group, 0.821; validation group, 0.799). The radiomics nomogram achieved a higher AUC (training group, 0.841; validation group, 0.814) and clinical net benefit. Besides, the radiomics nomogram provided a highest C-index (training group, 0.841; validation group, 0.820) in predicting prognosis for ccRCC patients. The radiomics nomogram can accurately predict the Ki-67 expression status and exhibit a great capacity for prognostic prediction in patients with ccRCC and may provide value for tailoring personalized treatment strategies and facilitating comprehensive clinical monitoring for ccRCC patients.
摘要：
Imaging plates can measure isotopes with alpha decay (such as radon and its progeny, americium, and so on). However, the detection efficiency of imaging plates is affected by alpha particle energy, types of imaging plates, and the overlapping effect. In this study, simulations were performed to analyze the relationship between detection efficiency and these three influence factors. The research findings suggest that BAS-TR and BAS-MS are well-suited for the detection of alpha particles with energy levels below 6.83 MeV and above, respectively. The track overlap effect correction method proposed in this study is applicable to both BAS-TR and BAS-MS image plates. The measurement results of radon progeny demonstrate that the correction method enhances the detection efficiency from 0.203 to 0.288. This study presents a valuable approach for selecting the appropriate image plate and correcting the track overlap effect in the measurement of alpha radioactive material concentration and other related information.
